你可以使用连接或者不使用连接，
使用联接
将tableb连接到tablea并选择所有不存在的id，然后将其插入tablea

INSERT INTO TableA(ID, QTY)
SELECT X.ID, 0 QTY FROM TableB X
LEFT OUTER JOIN TableA Y ON X.ID = Y.ID
WHERE Y.ID IS NULL

或
如果您想用两个表中的数据创建一个新表，那么使用下面的sql

INSERT INTO NewTable(ID, QTY)
SELECT X.ID, 0 QTY FROM TableB X
LEFT OUTER JOIN TableA Y ON X.ID = Y.ID
WHERE Y.ID IS NULL
UNION ALL
SELECT ID, QTY FROM TableA

使用not in

INSERT INTO TableA(ID, QTY)
SELECT X.ID, 0 QTY FROM TableB X
WHERE X.ID NOT IN (SELECT ID FROM TableA WHERE ID IS NOT NULL)

另一个选项是相关子查询和 NOT EXITS .

INSERT INTO `Table A`
            (`ID`,
             `QTY`)
            SELECT `ID`,
                   0
                   FROM `Table B`
                   WHERE NOT EXISTS (SELECT *
                                            FROM `Table A`
                                            WHERE `Table A`.`ID` = `Table B`.`ID`);